# curs_window 3x

    curs_window(3x)                                         curs_window(3x)

## NAME

           newwin, delwin, mvwin, subwin, derwin, mvderwin, dupwin,
           wsyncup, syncok, wcursyncup, wsyncdown - create curses
           windows

## SYNOPSIS

           #include <curses.h>

           WINDOW *newwin(int nlines, int ncols, int begin_y,
                 int begin_x);
           int delwin(WINDOW *win);
           int mvwin(WINDOW *win, int y, int x);
           WINDOW *subwin(WINDOW *orig, int nlines, int ncols,
                 int begin_y, int begin_x);
           WINDOW *derwin(WINDOW *orig, int nlines, int ncols,
                 int begin_y, int begin_x);
           int mvderwin(WINDOW *win, int par_y, int par_x);
           WINDOW *dupwin(WINDOW *win);
           void wsyncup(WINDOW *win);
           int syncok(WINDOW *win, bool bf);
           void wcursyncup(WINDOW *win);
           void wsyncdown(WINDOW *win);

## DESCRIPTION

           Calling newwin creates and returns a pointer to a new win-
           dow with the given number of lines and columns.  The upper
           left-hand  corner of the window is at line begin_y, column
           begin_x.  If either nlines or ncols is zero, they  default
           to  LINES - begin_y and COLS - begin_x.  A new full-screen
           window is created by calling newwin(0,0,0,0).

           Calling delwin deletes the named window, freeing all memo-
           ry associated with it (it does not actually erase the win-
           dow's screen image).  Subwindows must  be  deleted  before
           the main window can be deleted.

           Calling mvwin moves the window so that the upper left-hand
           corner is at position (x, y).  If the move would cause the
           window to be off the screen, it is an error and the window
           is not moved.  Moving subwindows is allowed, but should be
           avoided.

           Calling subwin creates and returns a pointer to a new win-
           dow with the given number of lines, nlines,  and  columns,
           ncols.   The  window  is at position (begin_y, begin_x) on
           the screen.  (This position is relative to the screen, and
           not to the window orig.)  The window is made in the middle
           of the window orig, so that changes  made  to  one  window
           will  affect  both  windows.   The subwindow shares memory
           with the window orig.  When using this routine, it is nec-
           essary  to call touchwin or touchline on orig before call-
           ing wrefresh on the subwindow.

           Calling derwin is the same as calling subwin, except  that
           begin_y and begin_x are relative to the origin of the win-
           dow orig rather than the screen.  There is  no  difference
           between the subwindows and the derived windows.

           Calling mvderwin moves a derived window (or subwindow) in-
           side its parent window.  The screen-relative parameters of
           the  window are not changed.  This routine is used to dis-
           play different parts of the  parent  window  at  the  same
           physical position on the screen.

           Calling  dupwin  creates  an exact duplicate of the window
           win.

           Calling wsyncup touches all locations in ancestors of  win
           that  are changed in win.  If syncok is called with second
           argument TRUE then wsyncup is called automatically whenev-
           er there is a change in the window.

           The  wsyncdown  routine  touches each location in win that
           has been touched in any of  its  ancestor  windows.   This
           routine  is  called by wrefresh, so it should almost never
           be necessary to call it manually.

           The routine wcursyncup updates the current cursor position
           of  all the ancestors of the window to reflect the current
           cursor position of the window.

## RETURN VALUE

           Routines that return an integer return the integer ERR up-
           on  failure  and OK (SVr4 only specifies "an integer value
           other than ERR") upon successful completion.

           Routines that return pointers return NULL on error.

           X/Open defines no error conditions.  In  this  implementa-
           tion

                  delwin
                       returns  an  error  if  the  window pointer is
                       null, or if the window is the parent of anoth-
                       er window.

                       This  implementation  also maintains a list of
                       windows, and checks that the pointer passed to
                       delwin  is  one  that it created, returning an
                       error if it was not..

                  mvderwin
                       returns an error  if  the  window  pointer  is
                       null,  or  if some part of the window would be
                       placed off-screen.

                  mvwin
                       returns an error  if  the  window  pointer  is
                       null,  or if the window is really a pad, or if
                       some part of the window would be  placed  off-
                       screen.

                  syncok
                       returns  an  error  if  the  window pointer is
                       null.

## NOTES

           If many small changes are made to the window, the  wsyncup
           option could degrade performance.

           Note that syncok may be a macro.

## BUGS

           The  subwindow  functions (subwin, derwin, mvderwin, wsyn-
           cup, wsyncdown, wcursyncup, syncok) are flaky, incomplete-
           ly implemented, and not well tested.

           The  System  V  curses documentation is very unclear about
           what wsyncup and wsyncdown actually do.  It seems to imply
           that  they  are only supposed to touch exactly those lines
           that are affected by ancestor changes.  The language here,
           and  the  behavior  of  the curses implementation, is pat-
           terned on the XPG4 curses standard.  The weaker XPG4  spec
           may result in slower updates.

## PORTABILITY

           The  XSI  Curses  standard,  Issue 4 describes these func-
           tions.

## SEE ALSO

           curses(3x), curs_refresh(3x), curs_touch(3x)

                                                            curs_window(3x)